I realize that the card is on the low-end of the performance scale but i figured that by increasing the video card memory by 8x (256mb to 2gb) i would at least see a little bit more stable FPS in CS:GO on similar settings under higher load situations. I saw that my max-fps dropped by 10-20FPS under normal running around!

My drivers are up to date and the card is on the performance setting under the control panel.

Would my 3gb of ram on my computer be the bottleneck now? Would increasing just the volume of ram help me or should i increase the speed also? Its currently 2x1gb sticks and 2x512mb sticks in the secondary slots. Im running W7 64bit, so i should be able to utilize more than 3gb of ram.

Would my 3gb of ram on my computer be the bottleneck now? Would increasing just the volume of ram help me or should i increase the speed also?

If you only changed one thing and performance was degraded, it heavily points towards the card, not existing hardware. If it was existing hardware, you'd really just be wondering why you didn't see as much of an improvement as you expected.

Regarding the video card, you did downgrade unfortunately. Memory size is far from the most important spec, especially if you aren't maxing the resolution or running multiple monitors or using ultra high texture packs. Your first bottleneck is going to be GPU core and memory clock speeds, and if you look at the specs off nvidia's site, you can see why:

8600GTS:
GPU Engine Specs:
10.8 Texture Fill Rate (billion/sec)

Memory Specs:
128-bit Memory Interface Width32 GB/sec

620:
GPU Engine Specs:
11.2 Texture Fill Rate (billion/sec)

Memory Specs:
64-bit Memory Interface Width14.4 GB/sec

So you actually downgraded on memory bandwidth by a lot. From http://www.gpureview.com/memory-band...ticle-356.html - "The amount and speed of the memory matter very little in comparison to the overall memory bandwidth. If you want a card with good memory, this number says it all."

This measures how quickly the card can access said memory. Having more doesn't help if it takes longer to access it.

Based on some of the info you gave me, I only got it up to 260w. I'm fairly certain you'll be okay - the 400w minimum rating includes other factors like CPU, motherboard, memory and hard drives. Unless you went all out, you're probably under 350w.

From nvidia: "Lower power configurations are possible using lower total power system configurations (CPU, Storage, Memory)."